Island



2 Sheets -Shet 1.

(No Model.)

E. L, SLOOUM. SBGONDARY ELECTRIC CLOCK.

Patented Nov. 26, 1889.

UNITED STATES PATENT OFFICE.

EASON Ii. SIJOCUM, OFPAWTUOKET, RIIODE ISLAND.

SECONDARY ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 416,148, dated November 26, 1889.

Application filed October 26, 1888. Serial No. 289,246. (No model.)

- To all whom it may concern.-

Be it known that I, EASON L. SLooUM, a citi-. zen of the United States, residing at Pawtucket, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Secondary Electric Clocks, of which the following is a specification.

The object of my improvement is to pro vide an electric chronometer having a device constructed for driving and looking a cheap and simple mechanism, which can be run, if

necessary, by a single battery-cell, insuring an absolutely correct action with a comparatively Weak current of electricity, and I accomplish this by the means illustrated in the accompanying drawings, in which Figure 1 is a front elevation; Fig. 2, a side elevation; Fig. 3, a rear elevation; Fig. 4, a

side elevation on the side opposite to that shown in Fig. 2; Fig. 5, the armature, and Fig. 6 the slotted pawl.

Similar letters refer to similar parts throughout.

Inthe drawings, A designates the frame which forms the bearing for the arbor a, which carries the minute-hand of a secondary electric clock. On this arbor is mounted a wheel 1), having one hundred and twenty teeth, so that whenever the wheel is moved forward two teeth the hand marks a minute on the imum and allowing the attraction of said arm ature to the magnet by an extremely light current of electricity, and also insuring freedom of action from any corrosion of said bearing.

D designates a coiled-wire spring secured into the post (1, Figs. 1 and which, with the post d supports the"cross-framQE which is the rear bearing of the arbor a. The other end of this springis secured in an auX iliary arm of the escapement, as will hereinafter more specifically be shown.

The driving and locking mechanism is 0011- structed with two arms g and 71 On the arm 9 is mounted a propelling-pawl c. This pawl is a thin strip of spring-steel, slightly bent to enable its end to engage with the gearwheel, and is slotted where secured to the arm to enable it to be adjusted to a proper length to engage the spur-wheel by the set-screw whichsecures it to said arm. This adj ustable propelling-pawl is one of the features of my invention and employed in no other electric clock. On the arm h of the escapement is formed an auxiliary arm h, having a rightangled lip 7L2, upon which is adjusted the prope1ling-pawl c, slotted in the same manner and similar to the pawl 0. These pawls are so adjusted (see Fig. 3) as to engage with the teeth of the wheel I) at points on the circumference of said wheel opposite to one another.

At the end of arm 71/ of the driving mechanism is the lip 7c, and on the arm g, at the point on the circumference of the wheel directly opposite, is the lip 7o, which as the escapement oscillates engage with the teeth of the wheel 1; alternately with one another and, looking with said teeth, prevent the wheel from moving forward until released.

IVhen the armature O is attracted by the electro-magnet F, the armature takes the position indicated by the dotted lines in the drawings, (see Fig. 3,) and the arms of the,

driving mechanism, secured, as described, to said armature, move with the same and take the position indicated by the dotted lines. As the armature is attracted toward the magnet, the pawl c presses against the teeth of the wheel I) and pushes the wheel forward one tooth. Immediately the lock it engages with the wheel and firmly locks the same. The lip IL2 in its forward movement carries with itself the end of the wire spring D and the wire takes the position indicated by the dotted lines. (See Fig. \Vhen the electro-magnet is devitalized, the force of the coiled-wire spring causes the arm of the driving mechanism to move back to its original position, and, moving back, causes the pawl c to press the wheel b forward another tooth,

the spring-pawl c springing into the space between the teeth of said wheel immediately in the rear of that before engaged by it, and the lock immediately engages with the wheel and locks the same. The oscillation of the arms of the driving mechanism alternately pushing and locking the geared wheel I) the number of pinions (via, one hundred and twenty) employed, move the minute-hand through a half-minute space 011 the dial by each attraction of the armature. On account of the shortness of this space the movement of the propelling-pawls and the action of the locks are of necessity very positive. This positive action of the pawls and locks forms an important feature of my invention, since it will prevent any possible fluctuations of the hands on the dial, which has been one of the serious objections in electric dials.

On the bridge at, secured to the frame, is mounted a rest adjustable by means of a screw. This rest serves as a stop for the armature and prevents the springing of the right arm of the driving mechanism from a too forcible blow.

In Fig. 2, O designates a lever pivoted at 0 to the bridge 00. To the aperture 0 in the end of this lever may be attached achain extending to the outside of the cloclccase, the function of the lever being to operate the mechanism of the clock and set the hands of the same by pressing the end of the lever forward against the propelling-anchor mechnism,as shown in the dotted line designated as 0 in Fig. 3.

I am aware that previous to this application secondary electric clocks have been constructed, as by patents issued to William I WVeisberger, No. 314,634, and to Charles E. Barschig, No. 30%,595, also to several others, but constructed on an entirely different principle from mine. In theirinventions the motion of the lever, after the devitalization of the electro-magnet, is secured by the use of a weight, or under the gravity system, so called, which is open to many serious objections.

In my construction both the armature and I the arms of the driving mechanism are made very light, and an ounce spring will serve to move the mechanism, which permits the use of a very light current of electricity, and I calculate to be able to run my mechanism by the employment of a single-cell battery. Under the gravity system, however, a heavy weight is employed, which, when the current is cut off, drops and carries with it the arm of the lever and the propelling-pawl. The ae tion is so strong that the pawl mustbe locked into the pinions to prevent displacement, and the distance of propulsion is so great that the hands fluctuate on the dial. Again, when a weight is used the clock must be mounted in just such a position, and the slightest variation in this position will cause serious displacement and fluctuations of the hands.

Experience has demonstrated that owing to the force necessarily employed to move the weight the propelling-pawl will occasionally jump two or more teeth. In my construction, however, as has been before described, the armature is loosely mounted upon an anti-friction V- shaped bearing, and owingto the use of a fixed spring, secured as described, and the escapement, secured as described, the clock will run in any position in which it may be placed, and the mechanism cannot be displaced by any jar, insuring absolutely correct movement of the hands under any circumstances. This is a point of great importance, since many secondary electric clocks are employed in mills, where it is necessary to have each clock run exactly like the main clock, and where, owing to the use of heavy machinery, a great amount of jar is communicated to the walls.

My clock, like a watch, can be run in any position or under any circumstances.

hat I claim as new, and desire to secure by Letters Patent, is-

1. The combination, substantially as hereinbefore described, of the electro-magnet, the armature, the driving and locking mechanism secured to said armature, the V- shaped anti-friction bearing, the arms 9 and 71/ of the driving mechanism, the slotted adjustable pawl c, mounted on the lip 7L2 of the arm of the driving mechanism, the slotted adj ustable pawl c, mounted on the arm g of the said driving mechanism, and the locks or stoppawls 7t 7t", mounted on opposite arms of the escapement, engaging and locking the geared wheel.

- 2. The combination, substantially as hereinbefore described, of the electro-magnet, the armature, the driving and locking mechanism, and the coiled-wire spring I), secured to the post (Z and the lip 7L2, for the purpose described The combination, substantially as hereinbefore described, of the electro-magnet, the armature, the arm extending from said armature and seen red to the driving and locking mechanism, the arms g and 7t of said escapement, the lip 7L2 of arm 7b, the slotted and adjustable pawls c and c, mounted on the arms 9 and h of said driving and locking mechanism and adjustable to said arms, as described, the locks 70 and 7s, mounted opposite to one another on the arms 9 and 71, respectively, alternately engaging with and locking the geared wheel, the geared wheel 1), and the WIN; spring D, secured to the shaft (Z and the lip 1 EASON L. SLOCUM.

In presence of TIO 

